Copper alloy for conducting electricity



Patented Jan. 1, 1935 UNl'l ED STATES PATENT OFFICE COPPER ALLOY FORCONDUCTING ELECTRICITY No Drawing.

Application April 20, 1934 Serial No. 721,460

1 Claim.

This invention relates to improvements in copper alloys, andparticularly, to a type of alloy capable of serving as a highlyefllcient carrier or conductor for electricity; the nature of the 5alloy being such that the same may be economically and practicallyfabricated as wire, contact points, contact terminals, switches, etc.

An equally important object of the invention resides in the provision ofa copper alloy which may be advantageously substituted for the nowprevalent class of electrical conductors, such for example, as thosespecies of electrical conductors made of copper; the alloy beingeifectually resistant to those detriments resulting from subjection ofelectrical conductors to atmospheric conditions, which, as is well knownin the art, brings about a progressive coating of the conductors, andespecially, copper electrical conductors, with carbon-copper-oxide andcorrosion, and hence, prematurely decreases the conductivity efliciencyof the same to a degree such as to render them ineflicient for continuedusage. Another object of the invention is to provide a copper alloyespecially advantageous for usage in the manufacture of electricalconductors, which possess a hardness materially greater than thatcommonly found in pure or substantially pure copper, as used at thepresent time, consequently, imparting to the alloy, a most desirablequality, i. e., so rendering the alloy that it will maintain itsoriginal or substantially original degree of hardness over a prolongedperiod of time, and against the aforesaid adverse conditions.

. As is well known to persons skilled in this art, electrical conductorsmade of pure or substantially pure copper, rapidly decrease in theirconductivity efficiency. This is mainly due to corroding and oxidationof such conductors, and in part, is because of the fact that with suchcoatings, the conductors present a most undesirable resistance toelectricity traversing the same, and hence, the heat thereby createdanneals the copper, softening it to a degree which is found in virgincopper, and by consequence, is impractical for the conduction ofelectricity.

For example, rolled sheet copper, when fabricated into electricalswitches, will in its initial performance amiably function. However,with exposure to those conditions incident to usage of I switches,corrosion and oxidation of the copper takes place, and consequently uponthis, its electrical conductivity is decreased to a material ex tent.That is to say, when the switch is in usage, arcing at its points ofcontact occurs and the heat thus transmitted to the switch causes theelectrical conducting metal thereof to lose its desirable and necessaryqualities of hardness, as well as its limited spring qualities; Theswitch becomes flabby and soft; its conductivity efliciency is greatlyimpaired. I have found, through extended experimentation, that underconditions such as above referred to, the electrical conductivity of thecopper is lost to such an extent that a switch element. constructedtherefrom actually becomes an element of resistance to the electricitytraversing the same, rather than functioning as an eflicient conductorfor the electricity. It is, therefore, manifest that a switch or otherconductor made of ordinary copper affords but a comparatively briefperiod of eflicient usage, and in addition to this, its continued usageinvolves major hazards, such as fire and the like, as well as entailingconsiderable loss of power upon part of a user thereof. Through theusage of an alloy constituted in accordance with my invention, I amenabled to produce a highly efficient electrically conductive metal,which is not only non-corrosive and nonoxidizing, but which affordselectrical conductivity efliciency far better than that of ordinarycopper. An alloy constituted in accordance with my invention will befound to beconsiderably harder than ordinary copper, and additionally,the improved alloy possesses a greater'degree of ductility. Because ofsuch structural characteristics, the alloy may be satisfactorily forged,extruded, rolled, or fabricated in accordance with such industrialmethods as are now known.

In order that the invention and the mode of production of theimprovedalloy may be thoroughly understood by workers skilled in the art, Ihave, in the following detailed description set out a satisfactoryembodiment of the same.

A typical formula for producing one form of the improved alloy isPercent Silver 1 Aluminum 4 Silicon Aluminum-titanium Calcium olybdate 1Iron mol bdenum 1 Copper-of an amount to complete a mass.

Through the usage of silver in the alloy, its conductivity is greatlybettered. The silver component furthermore serves to impart eflectualcorrosion and oxidizing resistant properties to the alloy. It alsofunctions, by reason of its ,high degree of electrical conductivity, asa means The aluminum-titanium in the alloy insures an advantageoushardening of the same, especially, in combination with its molybdenumcontent. The usage of calcium molybdate and iron molybdenum improves itscorrosion and stain resisting properties besides effecting a desirableage hardening of the same. The molybdenum content of these severalcomponents also prevents undesirable softening of the alloy and insuresa desirable, but not too great a degree of fluidity of the same; thelatter being especially advantageous in instances where the alloy is tobe cast. Furthermore, the molybdenum content of the calciummolybdate andiron molybdenum not only renders the alloy materially less subject todeterioration with exposure and usage, but it also insureshomogeneousness thereof, and at the same time, eliminatesintercrystalline brittleness of the product when it is subjected tomaterial temperatures.

At this point, it is to be noted that all, or'substantially all of themolybdenum, from the calcium molybdate and iron molybdenum, will enterinto the alloy, together with the iron. However, the calcium, at thetemperature of the molten metal will not enter the same, butrather, willproduce an efficient slag for the charge during the alloying process,sealing the heat and by consequence,v preventing oxidation thereof.

It is to be also understood that whereas different formulas of calciummolybdate and iron molybdenum may be used in my improved alloy, Ipreferably employ formulas of theseparticular components which,respectively, consist of molybdenum $3.90; silicon 0.18, and calcium55.92; and molybdenum 68.50, iron 31.20, and carbon 0.30. v

The aluminum-titanium component preferably consists of aluminum,approximately 60%, and

. titanium, approximately 40%.

The'final alloy consists 01:

Percent Silver 0. 84 Aluminum 3, 81 Silicon 0, 44 Titanium 0. 42Molybdenum 0. 37 Ir n 0.18 Calcium 0.06 Copper of an amount to completea 100% mass.

The molybdenum and iron content, it will be understood, will depend uponthe particular formulas of calcium molybdate and iron molybdenumintroduced into the charge.

The copper base of the improved alloy, through the usage of theheretofore specified components, becomes possessed of acomparatively-high melting point, and at the same time, its electricalconductivity efllciency is in no way impaired. The ductility of thecopper base is enhanced by the use of the aluminum component therewith,and also, the copper base appears to be hardened to an advantageousdegree by the use of the molybdenum and iron thereof, as well as havingits electrical conductivity efliciency increased because of thecompensating aifect produced by the silver component. The silvercomponent also serves to compensate for possible loss of electricalconductivity efficiency by reason of the titanium content of the alloy.In effecting a charge for the production of my improved alloy, thecomponents-silver, silicon, aluminum-titanium and iron molybdenum arepreferably introduced thereinto through master alloys. The calciummolybdate is added, alone, to the charge. The quantity of copper,sufllcient to complete a 100% mass (when including the aluminumcomponent) is added. A charge so constituted is brought to a temperatureof from 2100 to 2200 degrees Fahrenheit, being agitated to insure properalloying of the components. When the proper alloying is effected,heating of the charge is discontinued and approximately simultaneouslytherewith, the aluminum component is introduced into the mass and causedto be thoroughly alloyed therewith by agitation. In this way, the fullcontent of the aluminum component will be retained in the alloy, 1. e.,the burning off of the aluminum due to the high temperature of themolten charge will be prevented.

Under some manufacturing conditions or requirements, it may becomedesirable to impart or maintain a maximum degree of hardness to thealloy. In such instances, I have found it desirable to resort to aprocess of heat treatment of the alloy, to wit, heat treating the alloyand then quenching or rapidly cooling the same .in order that thepreviously dissolved non-metallic matters of the alloying componentswill be brought into a solid solution. Also, it may be v Percent Silver0. 84 Aluminum 3. 81 Silir'nn O. 44 Titanium- 0. 42 Molybdenum 0. 37Iron 0. 18 Calcium 0. 06 90. 74

COPPQT- FREDERICK J. MAAS.

